Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The in vitro and in vivo effects of lead on the activity of pyrimidine-5'-nucleotidase (P5N, E. C. 3.1.3.5) and delta-aminolevulinic acid dehydratase (ALA-D, E.C. 4.2.1.24) were studied. Incubation of blood with lead at concentrations of up to 3 mumol/l (about 60 micrograms/dl) did not appear to affect the activity of P5N, while the activity of ALA-D decreased dose-dependently with lead. Administration of lead caused a marked and rapid suppression of ALA-D in rats. The suppression of lead on P5N appeared to be a rather slow process. The decrease of its activity only came into effect 20 days after administration with lead. these findings suggest that lead induced P5N inhibition is a slow process while the suppression of ALA-D activity occurs much earlier.
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PMID:The in vitro and in vivo effects of lead on delta-aminolevulinic acid dehydratase and pyrimidine 5'-nucleotidase. 230 3

The method for determining erythrocyte pyrimidine 5'-nucleotidase (P5N EC 3.1.3.5) activity has been simplified using an automated high performance liquid chromatograph (HPLC). The activity determined by the simplified method agreed closely with that obtained by conventional methods. In 161 lead workers P5N activity declined linearly with increasing blood lead concentrations (Pb-B) between 20 and 80 micrograms/100 g, and correlated well with Pb-B (r = -0.87). For the same group of workers, correlation coefficients between Pb-B v ALA-D activity, zinc protoporphyrin, ALA-U, and coproporphyrin were -0.87, 0.73, 0.70, and 0.32, respectively. At Pb-B greater than or equal to 40 micrograms/100 g, the validity of P5N (1.86 at a cut off of 10 less than or equal to units) was higher than that of other indicators examined. P5N activity was fairly stable during the storage of samples for two weeks at 4 degrees C. Determination of P5N activity by this method may be a useful indicator in screening for moderate exposure to lead.
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PMID:A simplified method for determining erythrocyte pyrimidine 5'-nucleotidase (P5N) activity by HPLC and its value in monitoring lead exposure. 302 35

Among the biological exposure indices of lead, lead in plasma was the most direct indicator of current exposure. Lead mobilized into plasma as well as in urine could be used as an indicator of the internal dose of lead. The ratio of non-treated to restored activity of delta-aminolevulinic acid dehydratase (ALA-D) was a more specific index than ALA-D activity itself at low levels of lead exposure, excluding the familial or genetic variation in the activity. The methods using HPLC for determining heme intermediate improved the evaluation of the lead effect: delta-aminolevulinic acid in plasma, blood, and urine (ALA-P, ALA-B, and ALA-U), coproporphyrin in urine, and zinc protoporphyrin in blood (ZP). ROC (Receiver operating characteristic) curve analyses indicated that the diagnostic values for lead exposure decreased in the order ALA-D ratio > ALA-D activity = ALA-P > ALA-U = ZP. Pyrimidine 5'-nucleotidase activity or pyrimidine nucleotide concentrations in blood was also useful for the monitoring or diagnosis of lead intoxication. Using the HPLC method with inclusion compounds in the mobile phase, hippuric acid, methylhippuric acids, mandelic acid and phenylglyoxylic acid could be simultaneously determined in the urine of workers exposed to a mixture of toluene, xylenes, and ethylbenzene. The correction of the urinary metabolite concentration for specific gravity or creatinine allowed the more specific evaluation of the solvent exposure. In the biological monitoring of chlorinated hydrocarbons such as trichloroethylene, prolonged excretion of the metabolites resulted in a bias between metabolite concentrations and TWA levels of the solvent in a day. The background levels of 2,5-hexanedione (HD) were affected by acid hydrolysis conditions, age, sex and lipid metabolism. Substances hydrolyzed to HD in urine from non-exposed subjects were different from HD detected in the workers exposed to n-hexane. Urinary concentrations of N-acetyl-S-(N-methylcarbamoyl) cysteine (AMCC) served as an index of the average exposure to N, N-dimethylformamide during several preceding work days and may indicate the internal dose, while N-methylformamide may be an index of daily exposure. A simple and rapid method for the determination of urinary alkoxyacetic acids was recently developed for the biological monitoring of workers exposed to glycolethers and their acetates. Urinary butoxy acetic acid (free plus conjugated ones) could be simply determined by gaschromatography after acid hydrolysis of urine. The urinary acetone or methanol concentration determined by the head space technique was also useful for the biological monitoring of workers exposed to isopropanol and/or acetone, or methanol, respectively. Evaluation of exposure to the solvents described above could be carried out by comparing the urinary metabolite concentrations with reference values and the biological exposure index values which were defined as the urinary metabolite concentration corresponding to the threshold value for each solvent.
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PMID:[Studies on the evaluation of exposure to industrial chemicals]. 868 99

Oxidative stress is implicated in the pathogenesis of diabetes mellitus. Selenium supplementation has some benefits in experimental models of diabetes mellitus. This study evaluated whether dietary diphenyl diselenide, a simple synthetic organoselenium compound with antioxidant properties, reduces the streptozotocin (STZ)-induced toxicity. STZ-induced diabetic rats were fed with either standard and diphenyl diselenide (10 ppm) supplemented diets. In experimental trials, dietary diphenyl diselenide significantly decreased mortality rate (p<0.05) induced by STZ treatment. No correlation between this effect and glycemic levels were found. Diphenyl diselenide intake also promoted an increase in vitamin C, -SH levels (liver, kidney and blood) and in catalase (liver and kidney) activity, which were decreased in STZ-treated rats. In enzyme assays, diphenyl diselenide supplementation caused a significant improvement in platelets NTPDase and 5'-nucleotidase activities in STZ-induced diabetic rats when compared to the control and diabetic groups (p<0.05). Nevertheless, this supplementation did not modify the inhibition induced by STZ in delta-ALA-D activity. Our findings suggest that diphenyl diselenide compound showed beneficial effects against the development of diabetes by exhibiting antioxidant properties.
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PMID:Dietary diphenyl diselenide reduces the STZ-induced toxicity. 1787 Feb 24